Electric furnace



June 24 1924. 1,498,990

R. BEYER ELEC'IRIC: FURNACE Filed July 5. 1921 I5 Sheets-Sheet l 0 l Lf W13 /gyafU/MULW( j@ Afro/mfr 3 Sheets-Sheet 2 #v l'. \\W

R. BEYER ELECTRIC FURNACE Filed July 5, 1921 June 24, 1924.

nvm/TOR er 6M/WML #L5 ATTORNEY June 24, 1924. 1,498,990

R.BEYER ELECTRIC FURNACE Filed July 5., 1921 3 Sheets-Sheet I3 /N VE N TOI? Ano/Mfr Patented J une lZ4, 1924 UNITED STATES PATENT OFFICE.

ROBERT BEYER, OF MERAN, ITALY.

ELECTRIC FURNACE.

Application led July 5,

To all whom 'it may concern.'

Be it known that I, ROBERT BEYER, a citizen of Germany, residing at Meran, Italy, have invented certain new and useful Improvements in Electric Furnaces, of which the following is a full, clear, and exact speciiication.

My vinvention relates to improvements in electric furnaces, and the same has for its object more particularly to provide an electric furnace in Vwhich an exceedingly high temperature may be quickly produced and maintained with an economical use of electric current.'

Further, said invention has for its object to provide an electric furnace in which the heat producing means and the material to be heated are so insulated and protected as to prevent any undue loss of heat.

Further, said invention has for its object to provide an electric furnace in which the heating units are in the form of hollow slabs or plates having heating elements disposed therein, and iprovided in certain of their Walls or surfaces with openings to permitk of the assage of the radiant heat.

Fu-rt er, said invention has for its object to provide a furnace in which the heating units are so constructed and arranged that the same will not be injuriously Iaffected by the action of any gases or acids present or produced in the furnace during the operation thereof.

Further, said invention has for its object to provide an electric furnace in which the heat may be maintained underva vacuum.

Other objects will in part be obvious and in art be pointed out hereinafter.

otheI attainment of the aforesaid objects and ends my invention consists in the novel details of construction, and in the combination, connection and arrangement of parts hereinafter more fully described and then pointed out in the claims.

In the accompanying drawing showing an illustrative embodiment of the invention- Figure 1 is a front elevation showing one form of electric furnace constructed accord-l ing to, and embodying my said invention;

Fig. 2 is a horizontal section on the line 2 2 of Fig. 1;

Fig. 3 is a plan or top view showing one of the heating units, the same being partly broken away and in Section to show t e in; terior construction thereof;

1921. Serial N0. 482,334.

Fig. 4 is a transverse section thereof on the line 4-4 of Fig. 3;

Fig. 5 is a detail longitudinal section on the line 5 5 of Fig. 3, and

Fig. 6 is an enlarged detail section on the line 6-6 of Fig. 1 showing the adjustable resistance.

In said drawings 10 denotes the furnace as a whole which is mounted upon a stand comprising a frame 12 provided with legs 12a.

The furnace 10 comprises an outer rectangular double-Walled casing 11 formed as a water-cooled receptacle having an inlet 14 at itsbase, and an outlet 15 at its top adapted to be connected with a source of water supply. i

The casin 13 is yopen at its front and provided wit forwardly projecting bolts 16 to receive cover 17 adapted to be secured thereto by nuts 18.

By preference the cover 17 is made hollow and provided with an' inlet 19 and an outlet 20 whereby to connect the same with a source of water supply. The cover 17 is further provided with a pipe 21 extending entirely through said cover terminating at its outer end in a nozzle 22 provided with a valve 23 to permit of the ap lication of a pump for exhausting the interlor of the furnace.

To facilitate the handling of the cover the same is provided with handles 24, and to insure a fluid-tight joint between the cover 17 and the front of the casing 13 a suitable packing 25 is interposed between the same.

The interior of the casing 11 which constitutes the heating chamber has its inner side walls as well as its top and bottom provided with lining members 13* composed of plates of refractory material, such as zirconium, or

. a composition thereof.

rods orpencils 33 composed of carbon or compositlons 'of graphite and zirconium. The enlarged ends 33 of said elements 33 ex- ,tend through saidapertures32 and into the pockets V29, and have their ends connected in-series by split metal clamps 34 each hav- 1 ing its ends 35 secured together by a screw 36 and embracing one end of a metallic bond 37. In order to insulate and protect said clamps 34 and bonds 37, the same, together with the ends of the elements, are embedded in a mass of granulated or comminuted zirconium oxid.

p In order to enclose and protect the heating elements 33, the base 27 is provided upon its upper surface adjacent to opposite sides with undercut grooves or recesses 38 to receive a cover plate 39 provided in its central portion, lwhich registers substantially with the recessed portion or chamber 28 of the base 27, with a plurality of parallel openings 40 to permit of a certain amount of direct radiation ofvheat emitted by the elements 33.

Certain of the heating units 26 are provided in their upper sides along their edges with recesses 41 to receive the longitudinal tongues orprojections 42 on the edges of the adjoining sections.

. The end bonds 37a which serve to connect the heating or resistance elements 33 at the end of one heating unit 26 with the adjacent element 33 of the adjoining heating unit are carried through the rear of said units 26 through apertures 26a provided in outer side or bottom of the base 27, and the terminals 43, 43 extending from the heating elements 33 are carried through registering openings 43a provided in the lower insulating plate and the bottom of the-double-walled casing 13. Of said terminals, the terminal 43 is connected directly with the source of electric energy. i j

44 denote sockets secured to the frame 12 below the casing 10 having insulating sleeves 45 therein in which are supported the ends of a conductor bar 46 adapted for connection directly with the other conductor leading toa source of electric energy. Below rthe bar 46 is disposed a bar 47 of suitable insulating material having its ends supported in sockets 48 secured to the frame 12. 49 denotes a resistance element arranged in spiral form upon said insulating bar 47 and connected at one end to the other conductor 43 extending from the heating element 33.

50 denotes an adjustable Contact member slidably mounted upon'the conductor bar 46; the said 4Contact member 50 comprises a pair of spring pressed jaws 51 adapted to engage the spiral resistance 49 of the insulatmgy bar 47, and a pair of finger portions 52 for operating said jaws 51.

In operation the article to be treated may be placed in a suitable container and then v26 and the vsource of electric energy.

introduced ,into the heating chamber of the Hereupon the electric current is conducted by means of the bar 46, adjustable contact 50, resistance 49 to and Jfrom the terminals 43 extending from the heating u'rliits he desired strength of current being readily controllable by the adjustable contact 50 and the resistance 49. I

As the circuit is closed, the heating elements 33 will become incandescent, and the heat emitted thereby will, in part, be absorbed by the body of the heating unit 26,

and communicated to the heating chamber v of the furnace, and, in part, be transmitted l by radiation to the heating chamber through the openings 40 in the covers 38 of said heating units.

As aresult of the construction and arrangement of the several parts of the apparatus, it becomes possible to maintain for considerable periods of time a temperature ranging as high as 3000o C., and considerably higher temperatures v'for briefer periods of. time, without danger ofI injury to the apparatus.

It is to be noted that the temperature of the heating units 26 is capable of convenient control by varying the'conducting qualities of the heating elements 33, i. fby increasing or decreasing the'zirconium oxide content, and thereby render the element 33 more or less eilicient as an electric resistance v heating units each comprising a chamberedV base, heating elements therein, and a cover for said base, substantially as speciied.

2. An electric furnace comprisin an outer casing, a refracto lining, andieating units disposed withmfsaid-casing and forming the inner walls thereof; said'heating units each comprising achambered base,

heating elements therein, means for con- `1430' ducting current to said vheating elements, means for controlling the current supplied to said heating elements, and a cover for said base, substantially as specified.

3. An electric furnace comprising an outer casing, a refractory lining, and heating units disposed within said casing and forming-the inner walls thereof; said heating units each comprising a chambered base, heating elements therein, means .for conducting current to said elements, a variable resistance for controlling the current supplied to said heating elements, and a cover for said base, substantially as specified.

et. An electric furnace comprising an outer casing, a cover therefor, a refractory lining within said casing, and heating units disposed within said casing and enclosed by said lining; said heating units each comprising a hollow base, heating elements extending across said hollow base and connected with a source of electric energy, and a cover' for said hollow base, substantially as specified.

5. An electric furnace comprising an outer casing, a cover therefor, a refractory lining within said casing, and heating units disposed within said casing and enclosed by said lining; said heating units each compris-- ing a lhollow base, `heating elements extending across said hollow7 basev and connected with a source vof electric energy, a variable resistance interposed between lthe source of yelectric energy and said heating elements, and a cover for said'hollow base, substantially as specified.

6. An electric furnace comprising an outer water-cooled casing, a cover therefor, a refractory lining upon the inner Walls pf said casing, and a plurality ef heating units disposed within said casing and enclosed by said lining; said heating units each comprising a hollow base, supports thereon, electric resistance elements mounted in said supports and connected together and with a source of electric energy, and a cover for said base, substantially as specified.

7. An electric furnace comprising an outer Water-cooled casing, a cover therefor, a refractory lining upon the inner walls of said casing, and a plurality of heating units disposed within said casing and enclosed by said lining; said heating units each comprising a hollow base, ysupports thereon, electric resistance elements mounted -in said supports and connected together with a source of electric energy, a variable resistance interposed between the source of electric energy and said heating elements, and

disposed within said lining, said heatingunits each comprising a hollow base, longitudinal receptacles at its opposite edges, a filling of comminuted insulating material therein, aplurality of heating elements disposed in said base and having their ends extending into said longitudinal receptacles and the insulatinglling therein, means for connecting the adjacent ends of said elements, and means for closing said receptacles, substantially as specified.

9. An electric furnace comprising a double-walled casing, a hollow cover therefor, means for securing said cover .to said casing, a lining of refractory material within said casing, a plurality of separate heating units disposed within said refractory lining, means for interengaging the contiguous edges of said heating units;V said heating lunits each comprising a base havinga recessed central portion, and recessed portions at its opposite edges, a filling of comminuted insulating material disposed within the recessed edge portions, a plurality of parallel-disposed heating elements extending across said base and having their ends extending into said recessed ed e portions and into the insulating filling t erein, means for connecting the ends of said heating elements together, and a perforated cover removably secured'u on said hollow base, substantially as spec' ed.

10. An electric furnace comprising a double-walled casing, a hollow cover therefor, means for securing said cover to said casing, a lining of refractory material within said casing, a plurality of se arate heating units disposed -within saiI refractory lining, means for interengaging the contiguous edges of said heating units; said heating units each comprising a base having a recessed central portion, and recessed portions at its opposite edges, a filling of comminuted insulating material disposed within the recessed portions at the edges of said base, covers for said recessed edge portions, a plurality ofy parallel-disposed heating elements extending across said base and having their ends extending into said recessed edge portions and into the insulating filling ther-em, means for connecting the ends of said heating elements together, and witha source of electric energy, and a variable resistance interposed between said heating elements and said source of electric energy, and a perforated cover removably secured upon said hollow base, substantially as specified.

Signed at the city of New York, in the county and State of New York, this 27th day of May, one thousand nine hundred and twenty-one.

ROBERT BEYER. Witnesses:

Corman A. Dmramon, JOSEPH G. QUINN, Jr. 

